Dry powder fire extinguisher



Jan. 14, 1958 s, BQAL 2,819,763

DRY POWDER FIRE EXTINGUISHER Filed May 19, 1955 STEWART BOAL ATTORNEYS United States Patent DRY POWDER FIRE EXTINGUISHER Stewart Boal, Winnetka, lll., assignor to Margate Corporation, Chicago, Ill., a corporation of Illinois Application May 19, 1955, Serial No. 509,462

Claims. (Cl. 169-31) This invention relates generally to re extinguishers and more particularly, to portable re extinguishers wherein a pressurized gas is used to propel a dry powder fire extinguishing medium onto the fire.

Many various constructions of iire extinguishers have been made in the past in which a pressurized gas is used to propel a dry powder lire extinguishing medium onto the re. See, for example, U. S. Patent No. 2,580,448. All of these devices, however, have been large and unwieldy and, therefore, unsatisfactory for use as portable fire extinguishers and diicult to operate.

It is, therefore, an object of this invention to provide a lire extinguisher of the dry powder type that is relatively light, compact, and satisfactory for use as a portable tire extinguisher.

It is a further object of this invention to provide a portable iire extinguisher of the dry powder type which may be carried and operated by one hand.

lt is a further object of this invention to provide a fire extinguisher of the dry powder type that has an integral and compact valve which is easy to manufacture and opcrate.

My invention comprises an integral valve housing attached to the receptacle which contains the pressurized gas and powder tire extinguishing medium. The housing encloses the outlet valve and a manually `operated pilot valve. A chamber is provided within the valve housing containing a piston. The outlet valve is aiiixed to and actuated by the piston rod. A passageway leading through the pilot valve connects the chamber with the receptacle so the pressurized gases within the receptacle will enter the chamber to drive the piston and operate the valve when the pilot valve is opened. A counterbalancing means is provided to urge the outlet valve to closed position when the pilot valve is closed. A syphon tube or conduit connects the outlet valve with the bottom of the interior of the receptacle so that re extinguishing medium will be discharged from the bottom of the receptacle and all of the re extinguishing medium may be discharged from the receptacle, if desired, when the outlet valve is open.

Referring to the drawing in which there is shown a cross-sectional side view of a preferred embodiment of my invention, 1 denotes a receptacle containing a dry powder re extinguishing medium 2 and a highly cornpressed propellant gas in the area 3. The dry powder re extinguishing medium may be advantageously made of a mixture comprised substantially of bicarbonate of soda to which other ingredients to make the mixture moisture proof are added. However, any suitable mixture customarily used in dry powder re extinguishers can be used. The propellant gas may be nitrogen, compressed air, carbon dioxide or any other gas which is capable of being highly compressed in order to propel the dry powder out of the container and will not support combustion.

An integral housing 4 is screwed into one end of the receptacle and encloses an outlet valve denoted generally by 5 and a pilot valve denoted generally by 6. One end Nce of the housing has a handle 7 by which the extinguisher may be easily carried.

The `outlet valve 5 comprises generally a poppet-type valve 8 which is adapted to seat on valve seat 9. An engaging surface 18 of rubber, neoprene or other synthetic material may be superimposed upon the surface of valve S in order that an eiective iiuid tight seal will be made between it and seat 9. Valve 8 has a stem 10 which also serves as a piston rod connecting valve 8 with pneumatic piston 11 at its upper end. Pneumatic piston 11 is movable in a chamber 12 and may be advantageously provided with a washer 11a of rubber, neoprene or other suitable material in order that it will make a lluid tight seal with the sides of the chamber 12. The surface area of the piston 11 is made greater than that of the valve 8 so that the gas pressure in chamber 12 acting on the piston l1 will exert a greater force in a downward direction operating to open the valve 8 than in an upward direction to close the valve. A nozzle 13 iits into an aperture 14 made in the housing 4 which in turn connects with chamber 15 which is on the low pressure side of the valve 8. Nozzle 13 is so designed that it will disperse the re extinguishing medium in a constant even pattern. The housing 4 is extended beyond the end of the nozzle 13 so that the nozzle protrudes into an aperture 16 in the housing. This extension will protect the tip of the nozzle from becoming damaged or bent. Aperture 16 may be internally threaded so a discharge hose may be screwed into the said aperture. When a discharge hose is used the dispersing nozzle 13 is positioned at the discharge end of the discharge hose. lt is preferred to use such a discharge hose on the larger and heavier extinguishers so the discharging flre extinguishing medium may be directed upon the fire by merely directing the discharge hose and not the entire lire extinguisher.

A spring 17 continually urges the valve 8 to a closed position to aid in the function of valve 8 and to keep the valve from tending to open when the gas in the receptacle is at a low pressure due to the weight of the valve and thereby causing leakage. The spring 17 seats at one end on the outlet valve 8 and on the other end lon an angular ring 19 which is threaded into the bottom of the housing 4. Angular ring 19 in turn has threaded into it a conduit or syphon tube 20 which extends to the bottom part of the container 1.

Pilotvalve 6 comprises a fingertip control button 40 attached to a rod 41 which is adapted to engage the valve stem 42 of valve 43 when the button 40 is depressed. There is an indentation on rod 41 positioned so it will be inside V-packing 4 9 when the pilot valve 6 is in closed position. Valve 43 seats on a valve seat 44 and is kept in a closed position by the pressure of the propelling gas on the bottom of the valve 43 and by means of a spring 45' which continually urges the valve 43 to a closed position. Valve 43 when closed separates chamber 12 from area 3. When valve 43 is open chamber 12 is connected to area 3 by means of passages 46, 47 and 48. The V-packing 49 provides a uid tight seal between the rod 41 and the stem guiding plug 50 when pilot valve 6 is in open position and rod 41 is in depressed position so the indentation 70 is not inside V-packing 49. The valve 43, rod 4l, and valve seat 44 are held in place inside of the housing 4 by means of an angular sleeve 51 which is threaded into the housing 4. A guard 52 prevents inadvertent operation of or tampering with the fingertip control button 4t) and is adapted to be llicked to either side of the button 40.

I have found that the pilot valve 6 has a tendency to become clogged by the tire extinguishing powder when the pilot valve 6 is opened. This tendency is particularly pronounced after the extinguisher has been carried about so the tire extinguishing powder 2 has been shaken up.

sienes A screen' or filter 71 of cloth, fine metal mesh, or" other suitable tilter material may be advantageously provided at the beginning of passageway47 to keep the re extinguishing powder' particles from entering passageway 47' and clogging the pilot valve 6.

Passage 47 extends into another passage 60' which' in turn may be connectedI to a gauge, not shown in the' drawing, adapted to indicate the gas pressure i'n the oontiner. lt may also accommodate a pressure` release safety device which is not shown inthe drawing;

Plug 61 is screwed inl the end of the" housing to seal chamber 12 and provide for assembly and: rep'air of the valve parts. seals 62, 63 and 64 provide a' seal between adjacent parts to' prevent gas leakage;

Operation -ln order to operate the lire extinguisher, the4 handle 7 is grasped with one hand and the guard S2 is flicked` to one side with the thumb. Fingertip controlv button 40j is depressed by the thumb to cause rod 41 to depress in turn valve stem 42. Before rod 41 was depressed' the indentation 'i was positioned inside the V-packingw49, but when the rod 41 is depressed the indentation 70 passes completely below the V-packing 49 so the V-packing 49 will form a duid tight seal between the guiding plug 50 and rod 41 to prevent the leakage of gas between the guide plug 50 and the rod 41 into the atmosphere.. Since the cross-sectional area of the valve 43 isrelatively small, little force will be necessary to depress the button 40 as the combined opposing forces of spring 45 and the propellant gas pressure will be relatively small. As` the valve 43 is opened, gas from the area 3 of the container will pass through the passages 47, 46, around valve 43 into passage 48 and so into chamber 12. The pressure exerted upon piston 11 depresses it within chamber 12 and also piston rod` and valve 8. Valve 8 willl therefore open, allowing the lire extinguishing medium 2 to be forced from the bottom of the container 1 through conduit 20, around the valve 8, throughA chamber 1'5 and out through dispersing nozzle 13. When fingertip control button 40 is released, valve 43 will close bringing rodl 41 to upward position with the indentation 'I0y breaking the fluid tight seal between guide plug. 50 and rod 41, thereby permitting the pressurized gas `to escape from chamber 12, through passageway 4S and thence between guide plug 50 and rod4 41 intothe atmosphere.y When the gas pressure is released from chamber 12,. the gas pressure in area 3 and counter-balancing spring 17 will close valve 8 cutting off the-ilow of the iire extinguishing medium.

It is readily apparent that my invention provides an integral, portable, dry powder tire extinguisher which may be turned on and oiwithout having to be completely exhausted in one operation, easily operated by fingertip control and carried and operated by one hand. When a discharge hose is screwed into the aperture 16 with a nozzle at the discharge end thereof the extinguisher may be held and operated by one hand and the end of the discharge hose held in the other handy to direct the discharging ire extinguishing medium onto the llame. Ot course, it is understood that larger sizes of my tire extinguisher, too large to carry easily, can be' provided with a suitable carrying cart to give them addedportability.

While I have shown my extinguisher using adry powder fire extinguishing medium, it is obvious that anyI pressurized uid lire extinguishing medium could be used.

As various changes may be made in the form, construction and arrangements of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein isl to be interpreted as illustrative a'ndnotinI` any limiti-uglsens'e.

Iclaim':

1. In a re extinguisher of the type having a receptacle containing` a: fire' extinguishing medium and charged with a. pressurized uid medium, an integral release valve means atlixed to said receptacle and comprising a valve housing, an outlet valve for said extinguishing medium received in said housing and normally held in a closed position, a pneumatic piston connected to said outlet valve and adapted upon exposure to said pressurized medium to' open said outlet'valve, and manually operated pilot Valve means for controlling the application of pressure tosaid piston; the; improvement characterized by said pilot valve means comprising a valve rod slidably received in said housing and having a manually engageable portion projecting outwardly thereof, fluid passage means for exposing said pistonV to said pressurized duid medium comprising a control valve near the inner end of said valve rod and a passage surrounding an intermediate portion of said valve rod, an annular sealing ring surrounding anouter portion of said valve rod and: adapted' to form a seal between said valve rod and housing, means normally maintaining saidl valve rodl in; an outer position in said housing, said valve rod having an indented portion adapted to lie adjacent said sealing ring when said valve rodf is in said outer position whereby said sealing ring is ineffective to form av seal, said valve rod being adapted when moved inwardly of said housing toopen said control valve.

2.- The lire extinguisherA of claim l, further characterized by said iireextinguishing medium comprising a dry powdered material contained in the lower portion of the receptacle, the pressurized fluid medium being contained in the upper portion of the receptacle, said valve housing having a passage leading from said upper portion to said control valve, and said last' mentioned passage having iilter means therein to prevent said; dry powdered material from flowing to said control valve.

3. Inl a tire extinguisher of the' type having a' receptacle containing a lire extinguishing medium and charged with a pressurized uid medium', an integral release valve means aflixed to said receptacle and comprising a valve housing, an outlet valve' received in saidv housing and normally held inv a closed position, and manually operated pilot valve meansv for opening and closing said outlet valve; the improvement characterized by said outlet valve'- having a surface exposed at all times tothe interior of said receptacle and tending to maintain said outlet valve in a closed position, a piston received in said valve housing and connected toI said outlet valve, said piston being adapted upon exposure to said pressurized medium to openv said outlet valve, pilot valve means received in said valve housing and adapted when moved into a iirst position t'o-expose'said piston to the atmosphere and when moved into a second positionl to expose saidY piston to said: uid medium, and means normally maintaining said pilot valve means in saidl first position, saidpilot valve meansincluding a manually engageable portion exposed exteriorly of said valve housing and adapted to be manipulated to move said pilot valve means into said second position.

4. The iire extinguisher of claim 3, further characterized by said pilot valve means comprising a valve rod slidably received in said valve housing, sealing means near the outer end of said valve rod adapted to form a sealI between said valve rod and valve housing, and means to render said seal ineffective when said pilot valve means is in said rst position.

5f The iire extinguisher of claim 4, further characterized by saidsealing. means comprising an annular sealing ringA surrounding said valve rod', and `means providing a spacel between said valve rod and sealing ring when' said pilot valve means is in said first' position whereby tluid may'fl'ow through said spaceY to the atmosphere.

References Cited inthe tile of this patent UITED STATES PTENTS 2,674,326 Siebens pr. 6, 1954 

